Rapidly deployable and transportable high-power-density smart power generators

ABSTRACT

A portable solar photovoltaic (PV) electricity generator module comprises a plurality of smart power slat (SPS) units, each SPS unit comprising a plurality of solar cells electrically connected together based on a specified cell interconnection design, and, N at least one power maximizing integrated circuit collecting electricity generated by the plurality of solar cells. The plurality of SPS units are mechanically connected such that the SPS units can be retracted for volume compaction of the module, and can be expanded for increasing PV electricity generation by the module. The module can be used as part of an electric power supply with a maximum power point tracking (MPPT) power optimizer, storage battery and leads to connect to a load. The load can be AC or DC.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a U.S. National Phase patent application ofPCT/US2018/025548, filed Mar. 30, 2018, which claims priority to U.S.Provisional Application No. 62/483,333 filed Apr. 8, 2017, both of whichare hereby incorporated by reference in their entirety.

TECHNICAL BACKGROUND

The present disclosure relates generally to a solar photovoltaicelectricity generator and electric power supply, and specifically tocompact design of solar photovoltaic electricity generator for rapiddeployment and ease of transportation. Conventional glass-covered solarPV modules may capture light only from one face (monofacial), and powergeneration varies widely based on various factors, such as non-uniformlight conditions and presence of various localized and full shadingconditions affecting portions or all of the module.

SUMMARY

Disclosed herein is electric power generation modules for variousapplications based on innovative integration of solar photovoltaic (PV)cells and semiconductor microelectronics. This disclosure describesvarious structures and manufacturing methods for Rapidly Deployable &Portable Smart Power Generators (abbreviated as “RDP-SPG” and sometimesreferred to as generator modules) comprising a plurality of modular andscalable electric power-generating building blocks, known as Smart PowerSlat (SPS) units.

Specifically, this disclosure describes a portable solar photovoltaic(PV) electricity generator module (i.e., the RDP-SPG module) comprisinga plurality of smart power slat (SPS) units, each SPS unit comprising aplurality of solar cells electrically connected together based on aspecified solar cell partitioning pattern and electrical interconnectiondesign, and, at least one multi-modal power-maximizing semiconductorintegrated circuit collecting and delivering electricity generated bythe plurality of solar cells. The plurality of SPS units aremechanically or structurally connected such that the SPS units can beretracted for significant volume and surface area compaction of thepower-generating module, and can be rapidly expanded or deployed forenabling solar PV electricity generation by the module.

The RDP-SPG modules of this disclosure provide a number of majorbenefits, including but not limited to the following:

-   -   They use relatively lightweight structures, and provide very        high electric power densities and solar electric energy        densities (electric power and energy generation per unit        weight);    -   They are rapidly and easily retractable into compact volumes and        compact surface areas for ease of portability and transportation    -   They are rapidly and easily expandable (expansive modules) into        expanded three-dimensional (3D) bifacial light capture surface        areas for rapid deployment and efficient power generation in        target applications

The “Compaction Ratio” (the ratio of the module virtual enclosurevolumes when fully expanded to when fully retracted) of the RDP-SPGmodules of this disclosure is at least 10, and typically in the range ofat least 10 up to about 100 (typical compaction ratios are >50).

The modules of this invention can be designed for various targetapplications to provide maximum electric power levels in the range ofabout 10 watts (W_(p)) up to ˜3 kilo-watts (kW_(p)) per RDP-SPG module.The modules use building blocks (i.e. the SPS units) with distributedmaximum power harvesting electronics. The building blocks can be madefor various power scales (e.g., ˜10 to ˜100 W_(p)). Optionally, astorage battery unit is attached to the RDP-SPG module or an array ofRDP-SPG modules for electricity storage and uninterrupted electricitysupply depending on the application.

In another aspect, this disclosure teaches an electric power supplycomprising: a portable or transportable solar PV electricity generatormodule (i.e. the RDP-SPG module described above, or an array of theRDP-SPG modules connected together to provide higher power levels); anMPPT power optimizer for the generator module that receives electricityfrom the multi-modal power maximizing integrated circuits from each ofthe SPS units and generates aggregated power; an electricity storagedevice connected to the MPPT power optimizer, receiving at least aportion of the aggregated power from the MPPT power optimizer; and,output leads to deliver uninterrupted electricity to a load connected tothe electric power supply.

Compared to the conventional prior art PV modules, the generator moduleusing the bifacial SPS building block units of this disclosure are muchmore capable of generating maximum electrical power under variable andnon-uniform light (e.g., sunlight, diffuse daylight, or low light)conditions and also in presence of various localized and full shading ornon-uniform irradiance conditions affecting portions or all of theRDP-SPG module.

BRIEF DESCRIPTION OF THE DRAWINGS

The following description and associated figures teach illustrativeembodiments of the disclosure. For the purpose of teaching inventiveprinciples, some conventional aspects of the illustrative examples canbe simplified or omitted. The claims should be considered as part of thedisclosure. Note that some aspects of the best mode may not fall withinthe scope of the disclosure as specified by the claims. Thus, thoseskilled in the art will appreciate variations from the claimedembodiments that fall within the scope of the disclosure. Those skilledin the art will appreciate that the features described below can becombined in various ways to form multiple variations of the disclosure.As a result, the disclosure is not limited to the specific examplesdescribed below.

Please note that in the figures, relative geometrical dimensions are notnecessarily shown to scale.

FIG. 1A shows a plurality of Smart Power Slat (SPS) units interconnectedand stacked together when the RDP-SPG module is in a fully retractedstate for ease of portability and transportation.

FIGS. 1B and 1C show RDP-SPG module is in at least partially expanded ordeployed state for electric power generation, with FIG. 1B showing anopen-structure configuration (with through-slat open gaps betweenadjacent SPS units when expanded), and FIG. 1B showing aclosed-structure configuration (without through-slat open gaps betweenadjacent SPS units).

FIG. 2A-2E show several representative solar cell partitioning designsshowing bifacial high-efficiency solar cells partitioned into aplurality of sub-cells capable of scaling current (scaling down theelectrical current by a positive integer factor).

FIG. 3 shows a Smart Power Slat (SPS) unit with series-connectedmulti-modal MPPT chips (or alternatively, several SPS units with eachSPS unit having one multi-modal MPPT chip and the outputs of themulti-modal MPPT chips connected in electrical series).

FIG. 4 shows a flowchart showing the operation for distributed SPS andRDP-SPG power optimization using multi-modalmaximum-power-point-tracking (MPPT) integrated circuits.

FIGS. 5A-5E show examples of SPS units with one super-cell comprising aplurality of electrically connected partitioned sub-cells and onemulti-modal MPPT chip per SPS unit.

FIGS. 6A-6B show examples of SPS units with multiple super-cells andmultiple multi-modal MPPT integrated circuits (so-called MPPT chips)connected in electrical series.

FIGS. 7A-7B show examples of expanded open-structure modules with twodifferent SPS tilt angles to maximize bifacial light harvesting withnegligible wind resistance and water accumulation.

FIGS. 8A-8B show a bifacial SPS building block unit with in-laminateframe providing structural strength and other features for the laminate.

FIGS. 9A-9C show various types of electrical connections between SPSbuilding blocks for a power generating module.

FIGS. 10A-10F show examples of SPS in-laminate composite (includingfiber-reinforced polymer or FRP) frame design.

FIGS. 11A-11B show non-overlapping (or spaced apart) arrangement ofelectrically-connected sub-cells for the bifacial SPS building blocklaminates.

FIGS. 12A-12B show overlapping (or zero-gap) arrangement ofelectrically-connected sub-cells for the bifacial SPS building blocklaminates.

FIG. 13 shows an example flowchart showing the manufacturing processflow for making the SPS building block units for RDP-SPG modules.

FIG. 14A-14D show example of an open-structure (with through-slat opengaps between adjacent SPS units when expanded) RDP-SPG module in variousstages of expansion and retraction.

FIG. 15 shows structure of a folding thin-sheet connector used forelectrical and structural connections among the plurality of SPS unitsin an open-structure module.

FIG. 16 shows mechanically adjustable folding or pivoting sheetconnectors connecting multiple SPS units in an open-structureconfiguration (with through-slat open gaps between adjacent SPS unitswhen expanded).

FIGS. 17A-17F show an open-structure configuration (with through-slatopen gaps between adjacent SPS units when expanded) where short axes ofSPS units are perpendicular to virtual planes of the RDP-SPG module.

FIGS. 18A-18F show an open-structure configuration (with through-slatopen gaps between adjacent SPS units when expanded) where short axes ofSPS units are at a non-perpendicular angle with respect to virtualplanes of the RDP-SPG module.

FIGS. 19A-19C show a closed-structure module configuration (withoutthrough-slat open gaps between adjacent SPS units).

FIGS. 20A-20B show an example SPS building block with electrical andmechanical attachment leads.

FIG. 21 shows a table showing various representative preferred SPSbuilding block unit and RDP-SPG module designs.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

Embodiments of the present disclosure will now be described in detailwith reference to the drawings, which are provided as illustrativeexamples of the disclosure so as to enable those skilled in the art topractice the disclosure. Notably, the figures and examples below are notmeant to limit the scope of the present disclosure to a singleembodiment, but other embodiments are possible by way of interchange ofsome or all of the described or illustrated elements.

Moreover, where certain elements of the present disclosure can bepartially or fully implemented using known components, only thoseportions of such known components that are necessary for anunderstanding of the present disclosure will be described, and detaileddescriptions of other portions of such known components will be omittedso as not to obscure the disclosure. In the present specification, anembodiment showing a singular component should not be consideredlimiting; rather, the disclosure is intended to encompass otherembodiments including a plurality of the same component or nestedstages, and vice-versa, unless explicitly stated otherwise herein.Moreover, applicants do not intend for any term in the specification orclaims to be ascribed an uncommon or special meaning unless explicitlyset forth as such. Further, the present disclosure encompasses presentand future known equivalents to the known components referred to hereinby way of illustration.

Physical dimensions, directionality, shapes, voltages, currents, powergeneration amounts, number of sub-components used in a bigger componentare not limiting to the scope of the disclosure. They are used in theillustrative examples to facilitate the reader grasp the inventiveconcept and visualize the physical structure of the power generator.

Modular Bifacial Smart Power Slat Building Blocks for High-Density PVPower Generation

The primary unit building block of the RDP-SPG module of this disclosureis the Smart Power Slat (SPS) or the SPS building block unit, that is arelatively lightweight, relatively thin, bifacial solar photovoltaic(PV) electric power generating laminate, capable of efficientlyconverting light (sunlight or daylight photons) received on both itsopposite surfaces, including direct sunlight, direct or reflected lightfrom the ambience and diffused daylight, to electrical power.

Preferably, an SPS building block is: (i) relatively thin with athickness of less than about 3 mm and preferably in the range of about0.5 mm up to 2.5 mm, (ii) substantially planar, (iii) rigid orsemi-rigid with sufficient structural strength to retain its planarshape and to protect the partitioned solar cells within the laminate,(iv) elongated-shaped (e.g., such as rectangular-shaped) with aspectratio (i.e., average length to width ratio) in the approximate range ofabout 2 up to 20 (and more preferably between about 2 and 12; aspectratios smaller than 2 or larger than 12 are also possible), and (v) verylightweight with electric power density (defined as peak PV power amountgenerated by each SPS unit divided by weight of each SPS unit) in therange of about 50 W_(p) per kg to more than 200 W_(p) per kg.

An SPS laminate building block unit is a bifacially light-receivinglaminate having one or a plurality of bifacial solar cells (preferablysuch as at least two ˜156 mm×˜156 mm or nearly 6″×6″ bifacial solarcells, each partitioned into at least two sub-cells), and with eachbifacial solar cell partitioned into a plurality of (at least two)smaller sub-cells to obtain optimum electrical and mechanicalproperties.

An SPS laminate building block unit may comprise multiple (N) bifacialsolar cells, with each cell mechanically (such as using laser cutting ormechanical scribing or dicing) partitioned into a plurality of (M)electrically-connected sub-cells (e.g., ˜157 mm×157 mm crystallinesilicon bifacial solar cells), hence, the SPS unit having a quantity ofN×M sub-cells. Depending on the design, N is preferably an integer (oran integer plus a simple fraction) between 2 and 20, and M is aninteger, preferably between 2 and 16 (i.e., each cell partitioned into 2to 16 sub-cells). More preferably M=3 to 12. The sub-cells preferablyhave equal surface areas.

An SPS laminate building block unit SPS preferably has a slat activearea (i.e., solar cell area) width between half-cell-wide and2-cells-wide, with the cell-wide measure referring to the full sidedimension of a pre-partitioned crystalline silicon solar cell (althoughsmaller or larger SPS laminate widths may be used). The most preferredactive area width is a 1-cell-wide SPS. For instance, a one-cell wideslat has an active area width of about 157 mm (if the solar cells usedfor the slat have pre-partitioned areas of 157 mm×157 mm).

The SPS building block unit power is in the range of ˜10 W_(p) (e.g.,for N=2) and ˜100 W_(p) (e.g., for N=20). The peak power generation perSPS unit depends on the peak power per solar cell and the number ofpre-partitioned solar cells used in the SPS slat laminate. For variousproducts, a single RDP-SPG module may provide peak power in the range of˜20 W_(p) to ˜3 kW_(p) per module.

A single RDP-SPG module of this disclosure uses 2 to 45 (or even more)SPS laminate building block units. The number SPS of building blockunits in the RDP-SPG module is defined as ‘U.’

The solar cells used in the SPS building block laminate are relativelylow-cost mass-produced high-efficiency (preferably having >21%conversion efficiency under the Standard Test Condition or STC) bifacialsolar cells. The bifaciality factor of the bifacial solar cells shouldpreferably be over 60% and more preferably over 90% for enhancedelectricity generation.

Examples of solar cells for making the SPS building blocks include (butare not limited to): bifacial monocrystalline or multi-crystalline solarcells such as bifacial PERC (Passivated-Emitter Rear Contact) type solarcells and bifacial mono-crystalline Silicon Hetero Junction (SHJ; alsoknown as HIT) solar cells. Other choices of solar cells for the SPSbuilding block unit include high-efficiency tandem solar cellscomprising a combination of the above monocrystalline silicon solarcells with efficiency-enhancing wide-bandgap semiconductor cell stackssuch as those made of perovskites.

The SPS laminate unit with the laminated-embedded solar cells preferablyprovides effective SPS building block conversion efficiency of ≥19%(under STC) along with enhanced bifacial electricity generation.

Each full solar cell has a pre-partitioning size of at least ˜15.6cm×15.6 cm (area≥240 cm²). SPS unit may be nearly half-cell-wide (˜8 to12 cm) up to 2-cells-wide (˜32 to 36 cm), though smaller fractionalwidths (e.g., ⅓-cell-wide or ˜6 to 10 cm) may be used for smaller SPSunits.

FIG. 1A shows a plurality of SPS units 101 stacked together when theRDP-SPG module is in a fully retracted and compacted state. FIGS. 1B and1C show RDP-SPG module is in expanded state for power generation. FIG.1A shows expanded Open-Structure Design (bifacial SPS units arepreferably parallel to one another and the adjacent SPS units havethrough-slat gaps between them) and FIG. 1B shows expandedClosed-Structure Design (the adjacent bifacial SPS units arenon-parallel to each other and do not have through-slat openings betweenthem). In the open-structure design, angle θ may be fixed or adjustable.In the closed design, angle θ is adjustable (from 0° to 90°. 110 and 112are virtual (imaginary) planes on opposite sides of the slats for theopen structure (passing through the longer sides of the SPS units). 115is the folding or pivoting axes for the closed structure.

During the SPS building block manufacturing process, each full-size(e.g., with dimensions of at least ˜15.6 cm×15.6 cm, or full cellarea≥240 cm²) bifacial crystalline silicon solar cell is partitionedinto a plurality of (M is an integer, preferably between 2 and 16)smaller equal-area sub-cells, such that the completed SPS building blockunit has a plurality of N×M sub-cells in the laminate.

Partitioning (by laser cutting or mechanical dicing/scribing) of thefull-size solar cells into smaller area sub-cells serves multipleobjectives, including: (1) to scale down the SPS building block unitelectrical current for reducing the electrical ohmic losses andimproving the overall power generation efficiency, (2) to improvemechanical crack resistance of the laminated sub-cells and enhance theoverall mechanical resilience of the SPS laminate, and (3) to enable theuse of SPS-laminate-attached multi-modal MPPT power optimization chips.

Since the high-efficiency (>21% efficiency) monocrystalline siliconsolar cells produce current (STC short-circuit current I_(sc) andmaximum-power current I_(mp)) on the order of ˜9.6 A (or approximately10 A), partitioning of each solar cell into M sub-cells and electricalinterconnections of the sub-cells are done such that the SPS buildingblock current is lower than the full cell current by at least a factorof 2. The preferred SPS current scaling factor (compared to anon-partitioned full-cell current) is from 2 to 6, resulting in maximumSPS building block current in the order of ˜4.8 A (for factor of 2current down-scaling, assuming full-cell maximum current of about 9.6 A)down to ˜1.6 A (for factor of 6 current down-scaling).

For sufficient mechanical resilience of the SPS building block unit andcrack resistance of the laminated solar cells, each full-size solar cellmay be partitioned into at least 4 sub-cells (for further enhancedmechanical resilience of SPS laminate (for enhanced mechanicalresilience, optimal partitioning is 4 to 12 sub-cells per cell).

During manufacturing of the SPS building blocks, each full-size bifacialsolar cell is partitioned (for instance, using laser cutting, laserscribe and cell break, mechanical scribe and cell break, or mechanicaldicing of cells) into a pre-specified number of (M) sub-cells. M is aninteger between 2 and 16 resulting equal-area sub-cells per fullbifacial solar cell (e.g., crystalline silicon), and preferably between3 and 12 resulting bifacial sub-cells per full bifacial solar cell.

M is an integer and preferably may be expressed as multiple of 2integers between 1 and 8, such as:

-   -   M=K×L where K and L are between 1 and 8; for instance, M=2×3=6        or M=3×3=9 or M=2×2=4, etc. The most preferred designs use        M=3×1=3 or M=4×1=4 or M=2×2=4 or M=3×2=6 or M=3×3=9 or M=4×2=8        or M=6×2=12 or M=6×1=6 or M=4×3.

The sub-cells are formed according to a design pattern corresponding toM=K×L, and preferably have equal areas (for instance, partitioning of afull area bifacial solar cell with an area of 240 cm² into M=6 sub-cellsresults in an area of ˜40 cm² for all the resulting sub-cells. Thenumber of partitioning cuts depends on M=K×L. Partitioning of each fullsolar cell into M=2×2=4 or M=3×3 sub-cells requires 2 or 4 cellpartitioning cuts (preferably cuts along straight lines), respectively.For M=K×L, the total number (P) of partitioning cuts is P=(K+L−2).

The cell partitioning cuts are either electrical cuts or mechanicalcuts. Each electrical cut contributes to current reduction factor, andimproves mechanical resilience & crack suppression. Each mechanical cutimproves mechanical resilience & crack suppression, but has no impact oncurrent scaling.

When the PV current flows in the same direction in all sub-cellsresulting from a full-size cell, the partitioning cuts parallel to orperpendicular to the current flow direction are mechanical cuts andelectrical cuts, respectively. When the PV current flow alternates inthe opposite (180°) directions between adjacent rows of sub-cells (withrows being parallel to the current direction), all the partitioning cutsparallel to and perpendicular to the current flow direction areelectrical cuts (i.e., contribute to both electrical current reductionfactor and mechanical resilience).

FIG. 2A shows a representative design showing M=2×3=6 sub-cells andcurrent reduction factor of 2. Adjacent opposite-polarity busbars (orpositive and negative polarity leads of each sub-cell; the sub-cells mayor may not have busbars but for descriptions of the electricalconnections among the sub-cells in an SPS unit, the representativeexamples described here show sub-cells with busbars) 201 of adjacentsub-cells are electrically connected together in series (i.e., positiveleads of sub-cells 1-3 connected to negative leads of sub-cells 4-6). Inthis design, 3 sub-cells in each column are electrically connected inparallel and 2 columns are electrically connected in series for 2×current reduction.

An SPS building block laminate has N sets of these partitionedsub-cells, electrically connected to one another in either electricalseries or in hybrid electrical parallel and series (N is an integer oran integer+a fraction).

Among the three partitioning cuts, the two mechanical cuts are shown as202 a and the only electrical cut is shown as 204 a. Current flow inalternate rows of sub-cells is in the same direction (arrows 206 a and208 a).

FIG. 2B shows another representative design showing M=3×2=6 sub-cellsand current reduction factor of 3. Adjacent opposite-polarity busbars(or electrical leads) of adjacent sub-cells are electrically connectedtogether in series (i.e., positive leads of sub-cells 1-2 connected tonegative leads of sub-cells 3-4, positive leads of sub-cells 3-4connected to negative leads of sub-cells 5-6). In this design, 2sub-cells in each column are connected in electrical parallel, and 3columns are connected in electrical series for 3× current reduction.Among the three partitioning cuts, the only mechanical cut is shown as202 b and the two electrical cuts are shown as 204 b. Current flow inalternate rows of sub-cells is in the same direction (arrows 206 b and208 b).

FIG. 2C shows a third representative design showing M=2×2=4 sub-cellsand current reduction factor of 2. Adjacent opposite-polarity busbars(or electrical leads) of adjacent sub-cells are electrically connectedtogether in series (i.e., positive leads of sub-cells 1-2 connected tonegative leads of sub-cells 3-4). Here, 2 sub-cells in each column areconnected in electrical parallel and 2 columns are connected inelectrical series for 2× current reduction. Among the two partitioningcuts, the only mechanical cut is shown as 202 c and the only electricalcut is shown as 204 b. Current flow in alternate rows of sub-cells is inthe same direction (arrows 206 c and 208 c).

FIG. 2D shows a third representative design showing M=4×2=8 sub-cellsand current reduction factor of 4. Adjacent opposite-polarity busbars(or electrical leads) of adjacent sub-cells are electrically connectedtogether in series (i.e., positive leads of sub-cells 1-2 connected tonegative leads of sub-cells 3-4, positive leads of sub-cells 3-4connected to negative leads of sub-cells 5-6, positive leads ofsub-cells 5-6 connected to negative leads of sub-cells 7-8). Here, 2sub-cells in each column are connected in electrical parallel, and 4columns connected in electrical series for 4× current reduction. Amongthe four partitioning cuts, the only mechanical cut is shown as 202 dand the three electrical cuts are shown as 204 d. Current flow inalternate rows of sub-cells is in the same direction (arrows 206 d and208 d).

FIG. 2E shows a fourth representative design showing M=2×2=4 sub-cellsand current reduction factor of 4. Adjacent opposite-polarity busbars(or electrical leads) of adjacent sub-cells are electrically connectedtogether in series (i.e., positive lead of sub-cell 1 connected tonegative lead of sub-cells 3, positive lead of sub-cell 4 connected tonegative lead of sub-cells 2). Here, 2 sub-cells in each column are notconnected in parallel, and all four sub-cells are connected inelectrical series for 4× current reduction. Among the two partitioningcuts, there are no mechanical cuts, and there are two electrical cutshown as 204 e. Current flow in alternate rows of sub-cells is in theopposite direction (arrows 206 e and 208 e are in opposite directions).

Super-Cell Structure and Electrical Connections in an SPS Building Block

A super-cell structure is made of a plurality of sub-cells (which muchpreferably have equal areas) which are formed from partitioning offull-size solar cells, such as crystalline silicon solar cells. Eachsuper-cell structure has several (S=an integer or an integer+a fraction,2≤S≤6) full cells, with each full cell partitioned into M=K×L sub-cells;a super-cell has S×M=S×K×L sub-cells. The plurality of equal-areasub-cells in a super-cell are electrically connected to one anothereither in an all-series or in a hybrid parallel-series pattern, based onthe desired super-cell values for its maximum power (P_(SC-max)), itscurrent scale-down factor F_(SC-I) (relative to a single full-sizecell), and its voltage scale-up factor F_(SC-V) (relative to a singlefull-size solar cell). The P_(SC-max), F_(SC-I), and F_(SC-V) values areset by the S, K, and L values, and the electrical cuts. The preferredranges for the super-cell current and voltage scaling factors (currentscale-down and voltage scale-up factors) are: 2≤F_(SC-I)≤6 and10≤F_(SC-V)≤16 (e.g., F_(SC-I)=3, F_(SC-V)=12).

Assuming each non-partitioned full-size solar cell has ˜5 W_(p) maximumpower and 2≤S≤6, the super-cell maximum power is in the range of 10W_(p)≤P_(SC-max)≤30 W_(p) (most preferably 10 to 25 W_(p)). Eachsuper-cell has at least one pair of electrical power leads (positive andnegative leads).

In the Agile Smart Power™ products embodying the teaching of thisdisclosure, the electrical leads of each super-cell are preferablyconnected to the input leads of a multi-modalmaximum-power-point-tracking (MPPT) integrated circuit chip to enhanceelectrical power and energy generation by the RDP-SPG modules. Eachbifacial SPS building block has at least one super-cell connected to oneMPPT chip. Each RDP-SPG module has a plurality (U) of bifacial SPSbuilding block units.

There are several optimum super-cell designs (i.e., number of full cells& partitioning pattern) for achieving a good combination of distributedpower harvesting optimization granularity and cost associated with thenumber of multi-modal MPPT chips used in the RDP-SPG modules.

The preferred super-cell voltage scaling factor (i.e., number ofsub-cells or groups of sub-cells connected in series) is 12 to 14 (maybe as small as 10 and as large as 16) and the preferred super-cellcurrent reduction scaling factor is at least 2 (preferably 3 or larger).The combination of 12× voltage scale-up and 3× current scale-downfactors provide one optimum super-cell design for the combination ofoptimal MPPT chip operation, higher power conditioning capacity per MPPTchip, and excellent distributed power harvesting granularity.

Several representative optimum or near-optimum super-cell designexamples are shown below:

-   -   S=4, M=3×2=6; 2 electrical cuts, 1 mechanical cut, pairs of        columnar sub-cells connected in parallel, 12 pairs of sub-cells        connected in series, 12× voltage scale-up, 3× current        scale-down, ˜20 W_(p)    -   S=3, M=4×2=8; 3 electrical cuts, 1 mechanical cut, pairs of        columnar sub-cells connected in parallel, 12 pairs of sub-cells        connected in series, 12× voltage scale-up, 4× current        scale-down, ˜15 W_(p)    -   S=3, M=2×2=4; 2 electrical cuts, 0 mechanical cut, two adjacent        sub-cell rows connected in series, 12 sub-cells in 2 rows        connected in series, 12× voltage scale-up, 4× current        scale-down, ˜15 W_(p)    -   S=5, M=3×2=6; 2 electrical cuts, 1 mechanical cut, pairs of        columnar sub-cells connected in parallel, 15 pairs of sub-cells        connected in series, 15× voltage scale-up, 3× current        scale-down, ˜25 W_(p)    -   S=6, M=2×2=4; 1 electrical cuts, 1 mechanical cut, pairs of        columnar sub-cells connected in parallel, 12 pairs of sub-cells        connected in series, 12× voltage scale-up, 2× current        scale-down, ˜30 W_(p)    -   S=4⅔, M=3×2=6; 2 electrical cuts, 1 mechanical cut, pairs of        columnar sub-cells connected in parallel, 14 pairs of sub-cells        connected in series, 14× voltage scale-up, 3× current        scale-down, 23.3 W_(p)    -   S=4⅓, M=3×2=6; 2 electrical cuts, 1 mechanical cut, pairs of        columnar sub-cells connected in parallel, 13 pairs of sub-cells        connected in series, 13× voltage scale-up, 3× current        scale-down, 21.7 W_(p)    -   S=2, M=3×2=6; 3 electrical cuts, 0 mechanical cut, two adjacent        sub-cell rows connected in series, 12 sub-cells in 2 rows        connected in series, 12× voltage scale-up, 6× current        scale-down, ˜10 W_(p)        Laminate Attached (Super-Cell-Connected) Multi-Modal MPPT Chips        for SPS Building Blocks

Each SPS unit preferably has at least one multi-modal MPPT chip eitherwithin or connected to the SPS laminate and associated with a super-cellhaving a specified plurality of partitioned bifacial sub-cells. Eachsuper-cell has several partitioned and electrically-connected(all-series or hybrid parallel-series) sub-cells, and output positiveand negative leads for connection to the input leads of the multi-modalMPPT chip. Preferably, each super-cell may have from S=2 to S=6 solarcells (e.g., 2≤S≤6, with ˜240 cm² area solar cells, ≥5 W_(p) power),corresponding to S multiplied by M (or S×M) sub-cells in the super-cellblock. For 2≤S≤6 and full-cell power of ˜5 W_(p), the super-cell peakpower is ˜10 W_(p) to 30 W_(p) for each MPPT chip. More preferably 2≤S≤5(super-cell power of ˜10 W_(p) to 25 W_(p)) for optimum performance &cost. For 2≤S≤6 and 2≤M≤16, S and M are preferably chosen for S×M to be≥10, to allow for sufficient cell voltage scaling factor of at least 10if and when all sub-cells in the super-cell are connected in series.

The preferred super-cell output voltage range for optimum multi-modalMPPT chip operation is in the range of about 4.5 V to 12 V (and morepreferably ˜5 V to ˜10 V), and the preferred super-cell voltage scalingfactor is 10 to 16 (with the optimum super-cell voltage scaling factorbeing 12, 13, or 14).

The preferred super-cell output current reduction factor for themulti-modal MPPT chip is 2 to 6 (at least 3 is an optimum factor), sincethe maximum super-cell current for the reduction factor of 3× and 6× isabout ˜3.2 A and ˜1.6 A, respectively, well within the preferredoperating range of the multi-modal MPPT chip

Each super-cell is attached to one MPPT chip (power leads of super-cellconnected to the input power leads of the multi-modal MPPT chip), eachSPS unit is made of Z super-cells (Z is an integer equal to or greaterthan 1), and each SPS uses Z MPPT chips, embedded in or attached to theSPS unit structure.

The output leads of each super-cell are attached to the input leads ofone multi-modal MPPT chip and the output leads of multiple MPPT chipswithin each SPS building block and/or a plurality of SPS building blocksin an RDP-SPG module are connected together in electrical series orseries-parallel.

Assuming the RDP-SPG module uses a U number of SPS building blocks (U isan integer, preferably in the range of 2 to 45), the RDP-SPG module usesa total of U×Z super-cells and U×Z MPPT chips.

Series-Connected Multi Modal Maximum Power-Point Tracking (MPPT) Chips

A bifacial Smart Power Slat (SPS) building block unit uses at least 1multi-modal MPPT chip (preferably at least one SPS-laminate-attachedMPPT chip). The example in FIG. 3 shows multiple MPPT chips in the SPSbuilding block unit 310 within the dashed enclosure, with positive andnegative electrical terminals 302 and 304. Each MPPT chip connected to aplurality (e.g., 10 to 16) of partitioned solar sub-cells. The examplehere is shown with multiple series-connected multi-modal MPPT chips (oneMPPT chip for each super-cell).

There are N×M partitioned sub-cells in the SPS building block laminate.N bifacial solar cells are shown as 301, with each solar cellpartitioned into M equal-area sub-cells (M=K×L). There are (N×M)/Zpartitioned sub-cells in each super-cell, with a plurality of sub-cellsconnected in series.

The multi-modal MPPT chip provides a high (at least 90% andpreferably >98%) effective power optimization efficiency. The SPSmulti-modal MPPT chips work in cooperation with the RDP-SPG module levelor PV system level MPPT power optimizer, such as module or system levelpower converters or inverters with MPPT.

The multi-modal MPPT chip for distributed maximum-power harvesting inthe SPS building block units provides the following essential multiplemodes of operation (hence, multi-modal MPPT design):

-   -   Pass-through mode of operation: whenever there is no localized        weakening or disturbance of power generation by the solar cells        attached to the MPPT chip with respect to most of the other        solar cells in the RDP-SPG module, corresponding to when the        cells connected to the MPPT chip operate at or near their        maximum-power-point (MPP).    -   Optimizing mode of operation: which is a DC-to-DC switching mode        of operation, whenever there is some degree of localized        weakening or disturbance of power generation by the sub-cells        attached to the MPPT chip with respect to most the other solar        cells in the RDP-SPG module, corresponding to when the sub-cells        connected to the MPPT chip operate beyond a threshold allowance        away from their maximum-power-point (MPP) condition.    -   Sleep mode: corresponds to when the sub-cells attached to the        MPPT chip are not producing electric power and the MPPT chip is        not powered up, e.g., when the RPG-SPG module is retracted into        a non-deployed small volume or when there is no sunlight or        daylight.

The multi-modal MPPT chip for distributed maximum-power harvesting inthe SPS building block units may also preferably provide the followingadditional optional modes of operation:

-   -   Active bypass mode of operation: occurs when the sub-cells        attached to the MPPT chip produce negligible power with respect        to most of the other sub-cells in the RDP-SPG module but are        capable of powering up the MPPT chip.    -   Schottky Barrier Rectifier (SBR) bypass mode of operation:        occurs when the sub-cells attached to the MPPT chip produce no        power and the MPPT chip is not powered up, while most of the        other sub-cells in the RDP-SPG module are producing power (or        alternatively, when there is an electrical connection failure        within an SPS building block, preventing power generation by the        defective SPS unit).

FIG. 4 shows a flowchart showing the operation or algorithm fordistributed SPS and RDP-SPG power optimization. One or more seriesswitch M1 and one or more parallel switch M2 are used to control themode of operation within the multi-modal MPPT chip.

When the RDP-SPG module is in the retracted or contracted state and inits compact volume (or not deployed for power generation in its expandedoperating mode), the laminated-embedded bifacial solar sub-cells are notreceiving any power generating light. e multi-modal MPPT chips in theSPS building blocks are not powered up by the dark sub-cells since thestrings of electrically connected sub-cells attached to the MPPT chipsare not producing any voltage and power. The multi-modal MPPT chips arefully powered down and, therefore, are in the Sleep Mode (shut downmode).

When the RDP-SPG module is in the expanded or deployed state (i.e.,deployed for power generation in its partially or fully expandedoperating mode in its intended application), the laminate-attached MPPTchips in the SPS building block units are powered up by the super-cellsas long as the strings of electrically interconnected sub-cells attachedto the MPPT chips are receiving sunlight or daylight to producesufficient string voltage and power at the MPPT chips inputs. The MPPTchips are powered up and operate in one of the multi-modal functionalstates, as follows:

-   -   1. All multi-modal MPPT chips operate in the pass-through mode        whenever the strings of sub-cells in the SPS building blocks are        producing relatively electrically matched, comparable, and        normal electrical power amount within the RDP-SPG module.    -   2. One of more multi-modal MPPT chips operate in the optimizing        mode (switching optimization mode), for the multi-modal MPPT        chip(s) associated with one or more super-cells receiving less        light and producing less power than most of the other        super-cells in the SPS building blocks of the RDP-SPG module,        while the remaining multi-modal MPPT chips associated with the        normally operating super-cells (a majority of the multi-modal        MPPT chips) operate in the pass-through mode.    -   3. One of more multi-modal MPPT chips operate in the active or        passive bypass mode for the multi-modal MPPT chip(s) associated        with one or more super-cells receiving little to no light and        producing little power (for active bypass mode) to no power (for        passive bypass mode) compared to the other super-cells in the        SPS building blocks of the RDP-SPG module, while the other        multi-modal MPPT chips (a majority of the MPPT chips) operate in        the pass-through mode.

Sometimes a hybrid of 2 & 3 above is adopted, where some multi-modalMPPT chips are in bypass mode, some in optimizing mode, most inpass-through mode.

FIG. 5A shows a design example for Smart Power Slat (SPS) Building Block500A with 1 Super-Cell 501A and 1 MPPT Chip 502. SPS is a bifacial,thin, elongated, planar, rigid or semi-rigid, lightweight laminatehaving at least one super-cell (number of super-cells in the SPSlaminate is an integer Z≥1), and a plurality of N bifacial solar cells(wherein N=Z×S, and 2≤N≤20 depending on the SPS design needs), with eachbifacial solar cell partitioned into M equal-area sub-cells (M=aninteger between 2 and 16, preferably between 3 and 12).

The SPS unit may have its output positive & negative electrical rails503 and 504 connected to the output leads 505 and 506 on both ends,though output leads can be on one end of SPS laminate only.

The example in FIG. 5A shows a rectangular SPS unit (maximum power of˜20 W_(p)), having Z=1 super-cell, 1 MPPT chip: N=S=4, M=3×1. Thisdesign shows the positive & negative leads on both ends of the SPSlaminate, same current flow direction in adjacent sub-cell rows. Largerand higher power SPS units may be made using Z≥2, for instance 2supercells with 2 multi-modal MPPT chips connected in electrical series.

In the example shown in FIG. 5A, there are 4×3=12 sub-cells in this SPSdesign (1-cell wide by 4 cells long, corresponding to 1 sub-cell wide by12 sub-cells long with M=3×1 design). There are 2 electrical cuts and nomechanical cuts per cell. The SPS has 12× voltage scale up and 3×current scale down. Single row of sub-cells connected in electricalseries; using one multi-modal MPPT chip for 12 series-connectedsub-cells. Relative dimensions are not shown to scale (for instance, themulti-modal MPPT chip & support components, and partitioning gaps aremuch smaller than shown above). Approximate dimensions of the SPSbuilding block laminate with Z=1 super-cell represented in this designare: Width≈16 to 20 cm, Length≈65 to 70 cm.

Photo-generated PV electrical current flows in the direction of into thenegative busbars (or negative power leads) and out of the positivebusbars (or positive power leads), from negative towards positive leads.

FIG. 5B shows an alternative SPS design example for Smart Power Slat(SPS) Building Block 500B with 1 Super-Cell 501B and 1 MPPT Chip 502.The rectangular SPS unit (˜15 W_(p)) has Z=1 super-cell, 1 multi-modalMPPT chip: N=S=3, M=2×2. This design shows the positive & negative leadson both ends of the SPS laminate, opposite current flow direction inadjacent sub-cell rows.

There are 3×4=12 sub-cells in this SPS design (1-cell wide by 3 cellslong, corresponding to 2 sub-cells wide by 6 sub-cells long with M=2×2design). Two adjacent rows of sub-cells are connected in electricalseries; current flows in opposite directions in 2 adjacent sub-cellrows.

This design uses one multi-modal MPPT chip for 12 series-connectedsub-cells in 2 rows of sub-cells (current scaling down by 4× and voltagescaling up by 12×). There are 2 electrical cuts and no mechanical cutsper cell. Photo-generated PV electrical current flows in the directionof into the negative busbars (or negative power leads) and out of thepositive busbars (or positive power leads, from negative towardspositive leads. Approximate dimensions of the SPS building blocklaminate with Z=1 super-cell represented in this design are: Width 16 to20 cm, Length≈49 to 54 cm.

FIG. 5C shows another alternative design example for Smart Power Slat(SPS) Building Block 500C with 1 Super-Cell 501C and 1 multi-modal MPPTChip 502. A rectangular SPS unit (˜15 W_(p)), having Z=1 super-cell, 1multi-modal MPPT chip: N=S=3, M=4×1.

There are 3×4=12 sub-cells in this SPS design (active PV generation areaof 1-cell wide by 3 cells long, corresponding to 1 sub-cell wide by 12sub-cells long with M=4×1 design). Single row of sub-cells are connectedin electrical series; using one multi-modal MPPT chip for 12series-connected sub-cells, current scaling down by 4× and voltagescaling up by 12×. Photo-generated PV electrical current flows in thedirection of into the negative busbars (or negative power leads) and outof the positive busbars (or positive power leads), from negative towardspositive leads. Approximate dimensions of the SPS building blocklaminate with Z=1 super-cell represented in this design are: Width 16 to20 cm, Length 49 to 54 cm. There are three electrical cuts and nomechanical cut per cell.

FIG. 5D shows yet another alternative design example for Smart PowerSlat (SPS) Building Block 500D with 1 Super-Cell 501D and 1 multi-modalMPPT Chip 502. The SPS laminate may have its positive and negativeelectrical leads on one or both ends. A rectangular SPS (˜23.3 W_(p)),having Z=1 super-cell, 1 MPPT chip: N=S=4⅔, M=3×2. Same current flowdirection in adjacent sub-cell rows.

There are (4⅔=14/3)×6=28 sub-cells in this SPS design (1-cell wide by 4⅔cells long, corresponding to 2 sub-cells wide by 14 sub-cells long withM=3×2 design).

Columns of 2 sub-cells are connected in electrical parallel, rows ofsub-cells are connected in electrical series; using one multi-modal MPPTchip for 14 pairs of series-connected sub-cells. There are 2 electricalcuts and one mechanical cut per cell. Photo-generated PV electricalcurrent flows in the direction of into the negative busbars (or negativepower leads) and out of the positive busbars (or positive power leads),from negative towards positive leads. Approximate dimensions of the SPSbuilding block laminate with Z=1 super-cell represented in this designare: Width≈16 to 20 cm, Length≈75 to 80 cm.

FIG. 5E shows yet another alternative design example for Smart PowerSlat (SPS) Building Block 500E with 1 Super-Cell 501E and 1 multi-modalMPPT Chip 502. A rectangular SPS (˜25 W_(p)), having Z=1 super-cell, 1multi-modal MPPT chip: N=S=5, M=3×1. In this SPS design (1-cell wide by5 cells long, corresponding to 1 sub-cell wide by 15 sub-cells long withM=3×1 design), single row of sub-cells are connected in electricalseries; using one multi-modal MPPT chip for 15 series-connectedsub-cells.

Photo-generated PV electrical current flows in the direction of into thenegative busbars (negative power leads) and out of the positive busbars(positive power leads), from negative towards positive leads.Approximate dimensions of the SPS building block laminate with Z=1super-cell represented in this design are: Width 16 to 20 cm, Length 81to 86 cm. Per cell has 2 electrical cuts and no mechanical cut.

The representative design examples above indicate that numerous otherSPS building block designs are possible based on the teachings of thisdisclosure.

Preferred RDP-SPG Module and SPS Building Block Unit Designs

Optimal partitioning of each full-size bifacial solar cell into aplurality of M=K×L sub-cells using a combination of electrical cuts(resulting in electrical current & voltage scaling and improvedmechanical resilience and crack resistance of the resulting SPS) andmechanical cuts (resulting in further improved mechanical resilience andcrack resistance of the resulting SPS laminate) provides multipleenabling benefits, such as:

-   -   Scaling up the super-cell voltage (by F_(sc-V)) for the        multi-modal MPPT chip input voltage to be in an optimal range        (˜5 to ˜10 V);    -   Scaling down the super-cell current (by F_(sc-I)) to reduce the        power dissipation losses & enhance the RDP-SPG power;    -   Improving the overall mechanical resilience and sub-cell crack        resistance in the SPS units and RDP-SPG modules;    -   Allowance for using low-cost multi-modal MPPT chip with each        super-cell for distributed enhanced power generation and        distributed power maximization;

As discussed above, an SPS unit has Z super-cells and Z multi-modal MPPTchips (Z=an integer, preferably 1≤Z≤5), and each super-cell has Sbifacial solar cells (S=an integer or an integer plus a fraction,preferably 2≤S≤6, and more preferably 2≤S≤5), and each cell partitionedinto M=K×L sub-cells via K+L−2 partitioning electrical and mechanicalcuts (hence, each super-cell in an SPS unit having S×M=S×K×L sub-cells).

The numbers of sub-cells in each SPS unit and RDP-SPG module are Z×S×K×Land U×Z×S×K×L, respectively (and all the sub-cells preferably have equalareas, and have rectangular or square shapes)

As a representative example, a portable RDP-SPG module with ˜60 W_(p)rated peak power based on this disclosure may use 1-cell-wide SPS units,U=4, Z=1, S=3, M=2×2 (with 2 electrical cuts), resulting in RDP-SPGmodule (using 4 multi-modal MPPT chips) retracted dimensions of ˜17cm×˜65 cm×˜0.8 cm.

As another representative example, a transportable RDP-SPG module with˜600 W_(p) rated peak power based on this disclosure may use 1-cell-wideSPS units, U=10, Z=3, S=4, M=3×2 (with 2 electrical cuts+1 mechanicalcut), resulting in RDP-SPG module (using 30 multi-modal MPPT chips)retracted dimensions of ˜18 cm×˜208 cm×˜2.5 cm and a projected moduleweight of about ˜6 kg to ˜10 kg.

Bifacial SPS Building Block With Multi-Modal MPPT Chip PowerOptimization

In expanded/deployed mode, the RDP-SPG modules having bifacial SPSbuilding block units with laminate-embedded (or laminate-attached)multi-modal MPPT chips produce much more PV electric power andcumulative electric energy compared to either mono-facial buildingblocks (with or without multi-modal MPPT chip-assisted distributed poweroptimization) or bifacial building blocks without multi-modal MPPTchip-assisted distributed power optimization.

An SPS building block made using a combination of at least onesuper-cell having partitioned and electrically-connected bifacialsub-cells (partitioned from bifacial solar cells), and at least onemulti-modal MPPT chip provides a high-performance power generatingbuilding block which is very resilient and efficient for various RDP-SPGpower scales and operating conditions.

Compared to the conventional prior art PV modules, the bifacial SPSbuilding block units of this disclosure are much more capable ofgenerating maximum electrical power under variable and non-uniform light(e.g., sunlight, diffuse daylight, or low light) conditions and also inpresence of various localized and full shading conditions affectingportions or all of the RDP-SPG module.

In an RDP-SPG module using a plurality of SPS units, the overall modulePV power generation is further increased by the synergistic combinationof the enhanced bifacial SPS light capture and conversion from its twoopposite light-receiving faces, and distributed multi-modal MMPT powerharvest.

The multi-modal MPPT chips attached to the super-cells raise the SPS andRDP-SPG power generation via distributed optimization & mitigation ofmismatch effects among various super-cells & SPS units

Connecting SPS Super-Cells in Series for Z≥2

FIGS. 6A and 6B show three SPS super-cells (i.e. Z=3) connected inelectrical series. Example 1 shown in FIG. 6A shows SPS building blockusing 3 super-cells and 3 multi-modal MPPT chips (dimensions not shownto scale; sub-cell details and multi-modal MPPT chip to super-cellconnections not shown).

If there are more than 1 super-cells in an SPS unit, the plurality ofsuper-cells are preferably connect together in electrical series (byconnecting their associated multi-modal MPPT chip outputs in electricalseries). Middle super-cell block (Super-Cell 2) rotated 180 degrees vsSuper-Cell 1 and Super-Cell 3 to allow for straight series connectionsof three super-cell blocks.

For electrical series connections of super-cells, positive rail ofsuper-cell 1 (MPPT1) is connected to negative rail of super-cell 2, andpositive rail of super-cell 2 (MPPT2) connected to negative rail ofsuper-cell 3.

Example 2, shown in FIG. 6B, shows another type of series connections ofsuper-cells where positive rail of super-cell 1 (MPPT1) is connected tonegative rail of super-cell 2, and positive rail of super-cell 2 (MPPT2)connected to negative rail of super-cell 3.

Mitigating Wind Resistance/Lift and Water Accumulation

Some of the applications of the RDP-SPG modules of this disclosureinclude outdoor deployment of the expanded modules on the ground or onvarious building rooftops. For the applications which require outdoordeployment of the RDP-SPG module for an extended period of time (forinstance, power generation on a building rooftop), having a moduledesign with negligible wind resistance/lift will reduce the deploymentcost.

When deployed for power generation in their fully expanded states, theOpen-Structure RDP-SPG modules of this disclosure experience negligiblewind resistance/lift forces due to their relatively open structures withthe plurality of SPS units spaced apart from one another (SPS-to-SPSspacing on the order of the width of the SPS units). The negligiblewind-resistance/lift property of the RDP-SPG modules of this disclosureeliminates the need for ground or rooftop penetration, or for ballastingof the modules, enabling fast and labor-light drop-in-place deploymentof the expanded RDP-SPG modules. The Open-Structure RDP-SPG modules ofthis disclosure (along with the vertical or angled orientation of theSPS units) also eliminates any rain water or snow accumulation.

FIG. 7A shows an Open-Structure RDP-SPG Module example with U=10 SPSbuilding block units (fully expanded mode), i.e. having verticalorientation with respect to the virtual planes of the RDP-SPG module700A. Adjustable folding or pivoting sheet connectors 702 and 703 may bemade of perforated sheet or framed sheet for negligible wind resistance& drag. In FIG. 7A, all the sheet segments between the folding andpivoting axes 704 fold outwards upon retraction. Also in FIG. 7A, W iswidth of each SPS unit 701, and G is the spacing between adjacentparallel SPS units. The spacing G between two SPS units is G, which maybe equal to W. In FIG. 7B, SPS units are parallel to each other, but arenot perpendicular to the virtual plane of the RDP-SPG module 700B (eachopen structure RDP-SPG virtual plane contains one group of the longersides of the SPS building blocks).

Transparent Cover Sheets for the SPS Building Block Units

The preferred transparent cover sheet materials for the bifacial SPSbuilding block units of this disclosure include thin (˜0.025 mm to ˜0.50mm) fluoroplastic or fluoropolymer materials.

One suitable transparent fluoropolymer sheet material is the EthyleneTetra-Fluoro-Ethylene (ETFE) sheet, such as Tefzel or Teflon ETFE sheet,with the following properties:

-   -   Continuous service temperature: −100 to 150° C. (−150 to 300°        F.); good adhesion to EVA    -   High resistance to impact & tearing; inert to outdoor exposure;        excellent weathering resistance;    -   Self-cleaning material with substantially mitigated need for        cleaning;    -   High optical transmittance from UV through IR (except for far        IR); effective protection against moisture;    -   Typical sheet thicknesses from 25 μm to 125 μm; excellent        anti-stick and low frictional properties;    -   V-0 flammability classification (flame retardant).

Another suitable transparent fluoropolymer sheet material is theFluorinated Ethylene Propylene (FEP) sheet, such as Teflon FEP sheet,with the following properties:

-   -   Continuous service temperature: −240 to 205° C. (−400 to 400°        F.); good adhesion to EVA;    -   Excellent protection against moisture (about 5 times better than        ETFE);    -   Teflon FEP is about 2% more transmissive than ETFE and much more        transmissive than glass;    -   Typical sheet thicknesses from 25 μm to 125 μm; excellent        anti-stick and low frictional properties;    -   V-0 flammability classification (flame retardant).

The fluoropolymers ETFE and FEP films are excellent candidates for thebifacial SPS building block cover sheets because of their excellentoptical transparency over a wide spectral range (for example, superiorto low-iron float glass). Although thin (e.g., ˜0.025 to 0.125 mmthickness) fluoroplastic materials (e.g., ETFE or FEP) are the preferredcover sheet material choices, thin (preferably ≤0.85 mm),high-transparency, low-iron glass is an alternative cover sheet materialoption for the SPS units of this disclosure.

One suitable thin glass material candidate is the LEOFLEX™ glass fromAGC, which is a chemically-tempered (or strengthened using potassium ionexchange) aluminosilicate glass which is supplied in the thickness rangeof ˜0.55 mm to 1.3 mm (the lower end of the range is most suitable forthe SPS units of this disclosure), capable of tolerating bending radiusdown to ˜100 mm without glass breakage. The LEOFLEX™ glass providesoptical transmission of 91.6% (for 0.85 mm thick glass), comparable tostandard 3.2 mm thick low-iron glass (91.1%), but inferior to thetransmissivity values of ETFE and FEP.

Other alternative thin-glass cover sheet options include the Alkalineearth boro-aluminosilicate glass products, known as Corning® Eagle XG®,Corning® Eagle XG® Slim, and Corning® Willow® Glass brand glass productsfrom Corning; these glasses are as drawn to the desired final glassthickness which eliminates surface grinding & polishing processes thatadd cost and may introduce surface flaws. The thin Corning glassproducts are produced in the thickness range of 0.1 mm to 1.1 mm (withthe lower end of the thickness range being most suitable for the SPSbuilding block units of this disclosure). The coefficient of thermalexpansion (CTE 3-3.5 ppm/° C.) of Corning glass is well matched tosilicon. The Corning Alkaline earth boro-aluminosilicate glass providesgood optical transmissivity of ˜92% for the entire thickness range of0.1 to 1.1 mm, comparable to LEOFLEX, but inferior to FEP and ETFE.

Suitable Encapsulant Materials for the Bifacial SPS Building BlockLaminates

The bifacial SPS building block units use encapsulant sheets below thetransparent covers (fluoroplastics such as ETFE or FEP) to encapsulatethe sub-cells and frame on both light-receiving sides. The primaryencapsulant materials suitable for the SPS building block units areEthylene Vinyl Acetate copolymer (EVA), PolyOlefin Elastomer (POE), andIonomer-Based Encapsulants (IBE). EVA (such as PHOTOCAP® 15580P from STRSolar) is the most commonly used solar encapsulant material with vacuumlamination temperature of ˜145° C. to ˜150° C. and good opticaltransmission properties in the spectral range of interest (˜400 nm to1200 nm). POE (such as ENGAGE POE from The DOW Chemical Co.) is a viablealternative to EVA, and provides superior long-term power generation dueto lower degradation rate, higher electrical resistivity, betterprotection against moisture, and no acetic acid formation compared toEVA. IBE (such as PV5400 Series from DuPont) is another alternative toEVA, which is much stronger than EVA, and is 5 times stronger and up to100 times stiffer than polyvinyl butyral or PVB encapsulants); these IBEmaterials provide good adhesion to the cover sheets, are highlytransparent, need no curing, are non-yellowing, and provide excellentmoisture ingress protection and module strength. Similar to POE, IBEdoes not produce any acetic acid.

While the bifacial SPS building blocks may use any of the aboveencapsulant sheets in their laminates, the IBE material provides theadded benefit of additional mechanical stiffness and strength, making ita somewhat superior encapsulant material for making the SPS laminates.

Bifacial SPS Building Block Unit Laminate Structure

FIG. 8A-8B show an example SPS unit 800 comprising an elongated (e.g.,rectangular), thin (˜1 to 3 mm), planar, semi-rigid (or rigid),lightweight (˜0.1 to 0.5 g/cm²), high power density (˜50 to 200W_(p)/kg), bifacial SPS laminate using an in-laminate thin compositepolymeric frame 801 (for strength) and cover sheets 805 and 806 on thefirst and second SPS bifacial light-receiving surfaces. FIG. 8B is thecross-sectional view along the AA cutline. In this example, Z=1, S=4,M=3×3=9. Multi-modal MPPT chip and cell connection details are not shownfor clarity.

A thin (e.g., ˜0.5 to 3 mm) planar rigid composite polymer peripheralin-laminate frame 801 provides mechanical support and provideselectrical lead feedthroughs. A thin (e.g., 0.025 to 0.500 mm)transparent ETFE or FEP cover sheet 805 on Face 1 and 806 on Face 2provides mechanical and environmental protection while being opticallytransparent. In an alternative embodiment, thin (e.g., ˜0.1 to 0.8 mm)anti-reflection (AR)-coated high-transparency glass cover sheet may beused on the SPS faces. Solar encapsulant layers 807 and 808 on bifacialsides 1 and 2 of the sub-cells 802 are also optically transparent(materials used may be e.g., EVA, POE, or IBE). SPS negative lead 803and SPS positive lead 804 protrude from the frame 801.

Electrical Connections of the SPS Building Block Units in RDP-SPGModules

Depending on the product specifications (e.g., RDP-SPG voltage andcurrent requirements) and other factors such as the end-user maximumDC-voltage safety considerations, the electrical interconnections amongthe electrical leads of the SPS building block units in an RDP-SPGmodule may be in electrical series, parallel, or a hybridseries-parallel combination

In order to ensure user safety and eliminate the odds of electricshocks, the maximum open-circuit DC voltage (V_(oc)) of the RDP-SPGmodule (used in various applications) should be preferably limited toabout 60 V (and in most applications most preferably limited to ≤50 V).

Assuming a maximum open-circuit voltage (V_(oc)) of 0.70 V for eachcrystalline silicon bifacial sub-cell, the maximum open-circuit voltage(V_(oc)) of the SPS building block unit can be calculate as follows:V_(oc (SPS))≈0.70×Z×S×(Super-Cell Current Scaled-Down Factor). As anexample, for an SPS with Z=1, S=4, M=3×3 (2 Electrical-Cuts+2Mechanical-Cuts; current scale-down factor of 3):V_(oc (SPS))≈0.70×1×4×3=8.4 V; therefore, for this SPS design, up to 6SPS building blocks can be connected in electrical series in an RDP-SPGmodule, resulting in a series-connected multi-SPS string open-circuitvoltage value of 8.4×6≈50.4 V, meeting the safety requirement.

In multiple SPS units, all-series connections scale up the voltage,all-parallel connections scale up the current, and hybridseries-parallel connections scale up both the voltage and current.

FIG. 9A shows all-series connections of SPS building blocks (e.g., SPSunits using Z=1, S=4, M=3×3 using 2 Electrical-Cuts+2 Mechanical-Cuts,U=6, with SPS open-circuit voltage of ˜8.4 V) in an RDP-SPG module,resulting in the overall RDP-SPG module maximum open-circuit voltage ofV_(oc)≈50.4 V and maximum short-circuit current of I_(sc)≈3.2 A(relative dimensions not shown to scale, details not shown). Here, G=gapbetween adjacent units: 0.2 W≤G≤5 W; preferably: 0.5 W≤G≤2 W; mostpreferably: G≈W

Specifically, the RDP-SPG module 900A in FIG. 9A is shown in deployed(expanded) mode (mechanically adjustable folding or pivoting connectorsbetween adjacent SPS units are not shown for clarity). W is the width(perpendicular to the SPS view shown) of the SPS unit which may be inthe range of about half to twice the width of an equivalent full solarcell (e.g., 8 cm≤W≤35 cm). Typically W≈16 cm to 20 cm. Length of SPSUnit for this representative design example is L≈65 cm to 70 cm. SPSUnit thickness T≈1 mm to ˜3 mm in this example. 901A and 902A arerespectively the negative and positive leads of the RDP-SPG module 900A.

FIG. 9B shows an RDP-SPG module 900B using hybrid series-parallelconnections of the SPS unit building blocks. Hybrid series-parallelconnections of SPS building blocks (e.g., SPS units using Z=1, S=4,M=3×3 using 2 Electrical-Cuts+2 Mechanical-Cuts, No. of SPS units U=12,with SPS open-circuit voltage of ˜8.4 V) in an RDP-SPG module, resultingin the overall RDP-SPG module maximum open-circuit voltage ofV_(oc)≈50.4 V and maximum short-circuit current of I_(sc)≈6.4 A(relative dimensions not shown to scale, details not shown). G=gapbetween adjacent units: 0.2 W≤G≤5 W; preferably: 0.5 W≤G≤2 W; mostpreferably: G≈W. W (SPS width) is in the range of about half to twicethe width of a full solar cell (e.g., 8 cm≤W≤35 cm.) For hybridseries-parallel connections, first connect the SPS units in series andthen in parallel. 901B and 902B are respectively the negative andpositive leads of the RDP-SPG module 900B.

FIG. 9C shows an RDP-SPG module 900C using all-parallel connections ofthe SPS building blocks. This example shows all-parallel connections ofSPS building blocks (e.g., SPS units using Z=1, S=4, M=3×3 using 2Electrical-Cuts+2 Mechanical-Cuts, U=6, with SPS open-circuit voltage of˜8.4 V) in an RDP-SPG module, resulting in the overall RDP-SPG modulemaximum open-circuit voltage of V_(oc)≈8.4 V and maximum short-circuitcurrent of I_(sc)≈19.2 A (relative dimensions not shown to scale,details not shown). G=gap between adjacent units: 0.2 W≤G≤5 W;preferably: 0.5 W≤G≤2 W; most preferably: G≈W. Leads 901C and 902C arerespectively the negative and positive leads of the RDP-SPG module 900C.

Thin In-Laminate Frame for Bifacial SPS Building Block Units

The bifacial SPS building block unit preferably uses a thin,in-laminate, composite polymeric frame in order to provide furtherenhanced mechanical support & rigidity for extended lifetime(particularly for SPS building block units which use laminates withfluoropolymer cover sheets, such as ETFE or FEP, instead of glass coversheets, for less weight and higher power density). The in-laminate framematerial is sufficiently thin (e.g., ˜0.5 mm to <3 mm depending on theSPS unit dimensions) in order to meet the SPS unit weight and thicknessspecifications, i.e., provide power densities in the range of >50W_(p)/kg to ˜200 W_(p)/kg and SPS thickness≤3 mm. Width of the frame istypically 5 to 25 mm.

The in-laminate frame material preferably is an electrically-insulating,durable, rigid, proven, composite polymeric material with relatively lowmass density (density<1.9 g/cm³), with the composite materials proven inthe automotive and electronics industries being among the most preferredchoices.

The suitable composite polymeric materials which are applicable to thein-laminate frame include (but are not limited to): compositeglass-reinforced polyamide materials (having 15% to 40% glass content byweight), for instance, materials known as Ultramid, or composite glassreinforced polybutylene terephthalate known as Ultradur PBT materials,supplied by BASF Corporation.

Specifically, the thin in-laminate frames may be made of compositeglass-reinforced polyamide materials known as Ultramid® 8233G HS BK-106,or composite glass-reinforced polybutylene terephthalate known asUltradur® B4040G6 HR Black 15029 PBT materials, supplied by BASF.

Ultramid 8233G HS BK-106 is a heat stabilized, weather resistant, 33%glass-fiber-reinforced PA6 composite offering excellent strength,stiffness, high-temp. performance and dimensional stability.

Another material choice, Ultradur B 4040 G6 HR BK15029 is ahydrolysis-resistant, 30% glass-reinforced PBT/PET blend, providing goodmechanical properties & melt flow properties. Another material choice,Ultradur B 4300 G6 PBT is an easy-flowing, injection-molding PBT with30% glass fiber reinforcement for rigid, tough, and dimensionally stableparts. Another suitable material candidate for the in-laminate SPS frameand also the RDP-SPG folding (or pivoting) thin sheet connectors is theclass of printed-circuit board (PCB) materials.

The PCB sheet material may serve either solely as a structural materialor for the dual purposes of structural support and electricalconnections within and between the SPS units. If a PCB material is usedfor either the in-laminate SPS frame or the RDP-SPG folding (orpivoting) thin sheet connectors (or both), the PCB material mayoptionally include a thin layer of copper foil for providing copperelectrical interconnection runways and pads as needed.

If a PCB material is used for the in-laminate SPS frame, it may also beused to attach the MPPT chip and other components (capacitors, etc.)directly on it (instead of a separate PCB). One of the suitablematerials for the above-mentioned RDP-SPG applications is the standardrigid FR4 which is a glass-fiber epoxy PCB laminate, the most commonlyused PCB material. FR4 is flame-retardant UL94 V0, woven glassfabric+epoxy resin system, density≈1.9 g/cm³. Another suitable PCBmaterial for the above-mentioned RDP-SPG applications is CEM-3 (CEM:Composite Epoxy Material) which has a milky white color and is fairlysimilar to FR4.

The primary benefits of the PCB materials (FR4 and CEM-3) for theabove-mentioned applications (in-laminate SPS frame and RDP-SPGfolding/pivoting sheet connectors, discussed further below) include:mechanical strength and rigidity for thin (˜0.5 mm to 3 mm) sheets,excellent adhesion to the encapsulant materials, relatively low cost,excellent stability and lifetime.

The thin in-laminate frame enables production of reliable rigid orsemi-rigid SPS building block units without using heavy & thick rigidglass cover sheets. The thin in-laminate frame material must haveexcellent adhesion to the encapsulant material (EVA or another material)in the SPS laminate structure. The thin in-laminate frame used in theSPS building block unit laminate may either be a single-piece continuousperipheral frame or up to 4 straight pieces of the composite polymericmaterial arranged to form the frame for rigidity.

The thin composite frame may be either fully contained within the mainSPS laminate or its outer edges may protrude or extend somewhat beyondthe SPS laminate encapsulation to facilitate the extensions of the SPSelectrical leads. It also helps the mechanical and electricalattachments of the SPS building block units to the pair of mechanicallyor structurally adjustable folding (or pivoting or hinging) sheet orframe connectors.

The width of the peripheral frame (W_(F)) is much smaller than the widthof the SPS building block (W_(F)<<W), and is preferably 0.5 cm≤W_(F)≤3cm, with the smaller and larger SPS units using smaller and largerwidths, respectively. The thickness of the peripheral frame (T_(F)) issmaller than the SPS building block thickness (T_(F)<T≤3 mm), and ispreferably 0.5 mm≤T_(F)<3 mm.

A representative example of SPS in-laminate composite frame design isdiscussed below. The in-laminate SPS frames can serve at least some ofthe following purposes:

-   -   Provide enhanced mechanical rigidity and structural support for        the bifacial SPS laminate unit;    -   Facilitate implementation and attachment of the multi-modal MPPT        chip and supporting components such as capacitors (components        may be mounted on a designated portion of the frame itself,        particularly when using a PCB material such as FR4 or CEM-3 for        the frame material);    -   Support the electrical and mechanical (structural) connection        leads on the shorter sides of the SPS unit,

The in-laminate SPS frame design options include but are not limited tothe following:

-   -   Continuous frame without any extended segments beyond the SPS        laminate boundary;    -   Continuous frame with two or more extended segments beyond the        SPS laminate boundary;    -   Segmented frame without any extended segments beyond the SPS        laminate boundary;    -   Segmented frame with two or more extended segments beyond the        SPS laminate boundary.

The segmented frame design may allow the segments (e.g., 4 pieces perSPS) to be connected or snapped into each other to make an effectivesingle-piece frame. Segmented multi-piece frames may be manufacturedusing injection molding or laser-cut or stamped pieces from compositematerials.

These in-laminate SPS frame design options are shown in FIGS. 10A-F.FIG. 10A-10C show examples with SPS laminate boundary 1001 slightlybeyond the outer frame edge 1002. FIG. 10D-10F show examples with outerframe edge 1002 slightly beyond the SPS laminate boundary 1001. FIGS.10A and 10D show frame design with no protrusion for electrical andmechanical connections to the sheet connectors. FIGS. 10B and 10E showframe design with frame protrusion 1003 (having one on each end) forelectrical and mechanical (structural) connections to the sheetconnectors. FIGS. 10C and 10F show frame design with frame protrusion1004 (having two on each end) for electrical and mechanical (structural)connections to the sheet connectors. The continuous single-piece framesmay be manufactured using injection molding or laser-cut pieces fromcomposite materials.

Arrangements of Sub-Cells for the Bifacial SPS Building Block Laminates

The plurality of sub-cells in the bifacial SPS building block unit maybe arranged with respect to each other based on one of several designand manufacturing options, such as:

-   -   1. Co-Planar (Non-Overlapping Sub-Cells) With Tight Sub-Cell        Spacing: Co-planar sub-cells with the adjacent series-connected        sub-cell to sub-cell spacing of >0 mm up to about 1 mm (i.e.,        tightly spaced co-planar sub-cells in the bifacial SPS building        block);    -   2. Co-Planar (Non-Overlapping Sub-Cells)) With Larger Sub-Cell        Spacing: Co-planar sub-cells with the adjacent series-connected        sub-cell to sub-cell spacing of >1 mm up to ˜5 mm (i.e., larger        spacing of co-planar sub-cells in the bifacial SPS building        block);    -   3. Non-Co-Planar With Overlapping Sub-Cells: Non-co-planar and        edge-overlapping adjacent series-connected sub-cells with the        current-carrying (i.e., series-connected) edge pairs slightly        overlapping (edge subcell-on-subcell overlap width in the range        of a fraction of mm up to 2 mm) and stacked together; this        design option provides SPS building blocks with smaller surface        areas and higher power densities because of the overlapping        arrangement of the sub-cells.

The third design option (i.e. non-co-planar with overlapping sub-cells)simplifies the electrical series interconnections among the sub-cellssince the top edge (e.g., emitter or positive power lead) of a sub-cellcan be electrically connected to the bottom edge (e.g., base or negativepower lead) of an adjacent sub-cell using a suitable conductive epoxy(CE) or conductive adhesive (CA) material, hence, eliminating the needfor copper ribbon stringing of the sub-cells and soldering, andresulting in better aesthetics, enhanced power density, and possiblyimproved reliability.

FIG. 11A shows top view of a schematic diagram of sub-cell arrangementusing the “Non-Overlapping Sub-Cells” design (discussed as Options 1 & 2above for various spacings). In this example, an SPS unit is using Z=1,S=4, M=3×1 (12 sub-cells 1101 in the SPS unit; dimensions not shown torelative scale; most SPS laminate details such as ribbon connectiondetails not shown). FIG. 11B shows the cross-sectional view along thecutline AA shown in FIG. 11A. The in-laminate frame is shown as 1102with optional frame extensions 1103 for mechanical (structural) andelectrical connections. Copper ribbon series connections 1105 connectbackside base to frontside emitter of adjacent subcells 1101. SPSpositive and negative leads 1106 and 1107 respectively carry theelectricity generated by the SPS unit to the module-level MPPT poweroptimizer (AC or DC).

FIG. 12A shows top view of a schematic diagram of sub-cell arrangementusing the “Non-Co-Planar Overlapping Sub-Cells” design (discussed asOption 3 above). This representative example shown for an SPS unit usingZ=1, S=4, M=3×1 (12 sub-cells 1201 in the SPS; various dimensions notshown to relative scale; most SPS laminate details such as the laminatestructure details not shown). FIG. 12B shows the cross-sectional viewalong the cutline AA. The in-laminate frame is shown as 1202 with frameextensions 1203 for mechanical (structural) and electrical connections.SPS positive and negative power leads 1206 and 1207 respectively carrythe electricity generated by the SPS unit to the module-level MPPT.Overlapping connections 1205 connect base to emitter of adjacentsub-cells using conductive adhesive at the adhesive joints 1204.

FIG. 13 shows an example flowchart showing the manufacturing processflow for making the SPS building block units for RDP-SPG modules.Persons skilled in the art would appreciate that the steps can be variedwithin the scope of this disclosure depending on the design of the SPSbuilding block.

Mechanically Adjustable Folding (or Pivoting) Sheet Connectors forOpen-Structure RDP-SPG

In one embodiment, each RDP-SPG module is made of a plurality ofbifacial SPS building block units and preferably a pair of mechanicallyadjustable folding (or pivoting or hinged) thin sheet connectorsattached to the shorter sides of the SPS building blocks (for expansionand retraction). The pair of adjustable folding (pivoting) thin sheetconnectors fully enable rapid (e.g., in seconds) expansion (fordeployment) and retraction (for portability/transportability), andelectrically connect the SPS units in the desired interconnectionarrangement (all-series, hybrid series-parallel, or all-parallel) forefficient RDP-SPG power delivery. The electrical connections to both thepositive and negative polarities of each SPS building block unit may bemade either on just one of or both the shorter sides of the SPS unit viaone or both the folding (pivoting) thin sheet connectors, depending onwhether the SPS electrical leads (+ and − leads) are provided on one orboth ends. The partially extended to fully extended states of theRDP-SPG module correspond to deployment mode from lower to higher powergeneration amounts, respectively.

The pair of mechanically adjustable folding (or pivoting or hinged) thinsheet connectors are made using durable composite polymeric materialsand highly reliable folding or pivoting structures capable of numerousexpansion & retraction cycles without failure (other materials such astransparent fiberglass or PET sheets may be used).

To provide allowance for on-demand rapid expansion and retraction withexcellent reliability and extended lifetime, the mechanically adjustablethin sheet connectors may use a plurality of rotating pivots or foldingaxes in their designs, enabling from full retraction to full expansion.

FIGS. 14A-14D show example of an open-structure RDP-SPG module capableof retraction and expansion. Representative example of an RDP-SPG moduledesign with U=10 bifacial SPS building block units showing the module ina fully retracted or compacted condition (various dimensions in theschematic diagram below not shown to relative scale).

Assuming RDP-SPG module using a plurality of (i.e. ‘U’ number of) SPSbuilding block units, each of the pair of mechanically adjustable thinsheet connectors uses (2U−1) folding axes (or rotational pivots); forinstance, an RDP-SPG module using U=10 SPS building block units uses apair of mechanically adjustable thin sheet connectors, with eachconnector having 19 rotational pivots or folding axes (with 10 connectedto the SPS units and 9 folding or rotating axes located in between theSPS units).

Assuming a fully extended SPS unit-to-unit gap of G≈W and the SPS unitdimensions of W (width), L (length), and T (thickness), the effectivedimensions and volume of the RDP-SPG module with U number of SPS unitsin the fully expanded and retracted states are:

RDP-SPG Module dimensions & volume when fully expanded:V_(E)=L×W×(U−1)×W=L·W²·(U−1). For instance, for L=66 cm, W=18 cm, T=0.2cm, U=10, then volume is V=66×18²×9 cm³=192,456 cm.³

RDP-SPG Module dimensions & volume when fully retracted:V_(R)=(L+W)×W×U×T. For instance, for L=66 cm, W=18 cm, T=0.2 cm, U=10leads to a retracted volume of V=84×18×10×0.2 cm³=3,024 cm.³

Ratio of V_(E)/V_(R)=192,456/2,376=81 in the above example.

For this example, the volume compaction ratio is ˜81, meaning that theRDP-SPG unit can be compacted in volume by a factor of ˜81 compared toits deployment mode, for ease of portability and transportation.

The mechanically adjustable thin sheet connectors are preferably made ofrelatively thin (e.g., ˜0.5 to 3 mm in thickness), lightweight, durable,composite polymeric material sheet sections with pivoting or foldingfeatures (other materials such as transparent fiberglass may be used).

The suitable composite polymeric materials which are applicable to thefolding (or pivoting) thin sheet or framed connectors include (but arenot limited to): composite glass-reinforced polyamide materials (having15% to 40% glass content by weight), for instance, materials known asUltramid, or composite glass reinforced polybutylene terephthalate knownas Ultradur PBT materials, supplied by BASF Corporation.

Specifically, the mechanically adjustable folding (or pivoting) thinsheet or framed connectors may be made of composite glass-reinforcedpolyamide materials known as Ultramid® 8233G HS BK-106, or compositeglass-reinforced polybutylene terephthalate known as Ultradur® B4040G6HR Black 15029 PBT materials, which are supplied by BASF Corporation.

One suitable material of choice, Ultramid 8233G HS BK-106, supplied byBASF, is a heat stabilized, weather resistant, 33%glass-fiber-reinforced PA6 injection molding composite offeringexcellent strength, stiffness, high temperature performance anddimensional stability Another material choice, Ultradur B 4040 G6 HRBK15029 is a hydrolysis-resistant, 30% glass-reinforced PBT/PET blend,providing good mechanical properties & melt flow properties. Anothermaterial choice, Ultradur B 4300 G6 PBT is an easy-flowing,injection-molding PBT with 30% glass fiber reinforcement for rigid,tough, and dimensionally stable parts. Other materials of interest forthe adjustable folding/pivoting sheet connectors include otherhigh-durability, lightweight composite polymeric materials used in theautomotive industry.

Specifically, FIG. 14A shows a fully retracted RDP-SPG module. T_(SPS)is the thickness of a single unit. Fully retracted virtual enclosurevolume: V_(R)≈(L+W)×W×U×T_(SPS). FIG. 14D shows fully expanded virtualenclosure volume: V_(E)≈L×W×(U=1)×W=L×W²×(U−1). Elements 1401 show thefolding or pivoting axes in adjustable thin sheet connector 1403 (shownin FIG. 14D) on one side, and 1402 show the folding or pivoting axes inadjustable thin sheet connector 1404 (shown in FIG. 14D) on the otherside. FIGS. 14B and 14C show partially expanded configurations with thegap between the adjacent SPS units gradually increasing towards fullexpansion.

FIG. 15 shows partially expanded view of a folding-thin-sheet connectorstructure 1503 for open structure RDP-SPG module. The plurality of thebifacial SPS building block units (not shown in FIG. 15 ) are preferablyconnected together in an RDP-SPG module using a pair of expandable andretractable folding-thin-sheet connectors like 1503 on each short end.The bottom end lines F1 and F8, and the bottom folding intersectionlines F2 through F7, are attached to one of the two shorter sides ofeach of the SPS building block units (not shown). The thin connectorsheets (which serve as both mechanical and electrical connectors amongthe SPS units) can pivot around the top folding lines f1 through f8 andthe bottom folding lines F2 through F7, providing the capability forrapid extension and retraction of the SPS units. The segments ofconnector 1503 are made of rigid or semi-rigid thin sheets preferably <2mm thickness, area≈W·(G/2).

FIG. 16 shows a mechanically adjustable folding or pivoting sheetconnectors 1603 and 1604 for open-structure RDP-SPG modules. Thisexample shows single-fold-per SPS connector sheet between adjacent SPSunits (though designs with multiple folds may be used). The 3D schematicview of FIG. 16 shows an RDP-SPG power module embodiment of thisdisclosure in a partially extended mode.

The folding connector sheets serve as both mechanical (structural) andelectrical connectors among the plurality of bifacial SPS units

1603 is adjustable folding connector sheet 1 attached to one of the twoshort sides of the Bifacial SPS units (example shown with 10 SPS units).1604 is adjustable folding connector sheet 2 attached to one of thetwo—SPG Module Shown in a Partially Expanded Mode. SPS units caneffectively capture light from various incoming angles on their bifacialsurfaces through their open structures.

There are a variety of preferred angular arrangements (angles of SPSunit planes) to connect and configure a plurality of SPS building blockunits and the pair of expandable & retractable multi-fold mechanical &electrical sheet connectors in the RDP-SPG modules of this disclosure.

In the preferred RDP-SPG designs, the longer axes of the SPS units areperpendicular to the axes of the pair of expandable & retractablemulti-fold mechanical & electrical sheet connectors. In one embodimentof the RDP-SPG modules of this disclosure, the shorter axes of the SPSunits (which are perpendicular to the longer axes of the SPS units) areperpendicular (having a fixed 90° angle) to the virtual plane of theRDP-SPG module comprising one set of the long axes of the SPS units,while all the SPS building block unit planes are parallel to each other,as shown in FIGS. 17A-B.

In another embodiment of the RDP-SPG modules of this disclosure, theshorter axes of the SPS units (which are perpendicular to the longeraxes of the SPS units) are non-perpendicular (having a fixednon-perpendicular angle) to the virtual plane of the RDP-SPG modulecomprising one set of the long axes of the SPS units, while all the SPSunit planes are parallel to each other, as shown in FIG. 18A-B.

In another embodiment of the RDP-SPG modules of this disclosure, theshorter axes of the SPS units (which are perpendicular to the longeraxes of the SPS units) have an adjustable angles (e.g., between >0° and90° to the virtual plan of the RDP-SPG module comprising one set of thelong axes of the SPS units, while all the SPS unit planes are parallelto each other.

FIG. 17A shows schematic diagram of the top view of an open-structureRDP-SPG module in a partially extended state. Adjustable foldingconnector sheet 1703 on one side has folding/pivoting axes F1-F10 andf1-f19. Adjustable folding connector sheet 1704 on the other side alsohas folding/pivoting axes F1-F10 (elements 1701) and f1-f19 (elements1702). FIG. 17B shows schematic diagram of a cross sectional view (alongAA plane shown in FIG. 17A), where the short axes 1711 of SPS units areperpendicular to top virtual plane 1710 and bottom virtual plane 1712 ofthe RDP-SPG module. FIGS. 17C-D are respectively the top view and thecross-sectional view of the structure shown in FIGS. 17A-B, but in fullyextended configuration. FIGS. 17E-F are respectively the top view andthe cross-sectional view of the structure shown in FIGS. 17A-B, but infully retracted configuration.

FIG. 18A shows schematic diagram of the top view of an open structureRDP-SPG module in a partially extended state (adjustable foldingconnector sheets 1803 and 1804 have segments folding outwards), wherethe short axes 1811 of SPS units are not perpendicular to top virtualplane 1810 and bottom virtual plane 1812 of the RDP-SPG module. The SPSbuilding block units are angularly disposed with respect to the pivotingaxes, but the units are parallel to one another. FIG. 18B showsschematic diagram of a cross sectional view (along AA plane shown inFIG. 18A), where it shows that the angle that the short axes of SPSunits make with the bottom virtual plane is 0°<θ<90° (non-perpendicular:0≠90°. FIGS. 18C-D are respectively the top view and the cross-sectionalview of the structure shown in FIGS. 18A-B, but in fully extendedconfiguration. FIGS. 18E-F are respectively the top view and the crosssectional view of an open structure shown in FIGS. 18A-B, but in fullyretracted configuration.

Closed-Structure RDP-SPG Module

FIG. 19A shows a schematic diagram of a closed structure RDP-SPG modulewith 10 (i.e. U=10) bifacial SPS building blocks, shown in a fullyretracted or compacted condition. Multiple Bifacial SPS Units areconnected in series or in parallel or in hybrid series-parallelconfiguration through their folding or pivoting axes 1901 and 1902 onthe opposite ends of SPS units. FIG. 19A-C show a design with theshorter sides of SPS units connected to the folding or pivoting axes. Itis also possible to make Closed-structure RDP-SPG modules with thelonger sides of SPS units connected to the folding or pivoting axes. InFIGS. 19A-C, L=Length of Bifacial SPS Unit (longer sides of SPS units).Width of Fully Retracted RDP-SPG Module=U×T_(SPS), where T_(SPS) is theSPS building block thickness. Fully Retracted Virtual Enclosure Volume:V_(R)≈L×W×U×T_(SPS). The positive and negative powers leads are shown aselements 1920 and 1921.

FIG. 19B shows the structure in FIG. 19A in a partially expandedcondition. The adjacent SPS pair angles θ₁ through θ₈ are adjustable ina range between 0° and 360° (or a subset of angles in this range), andthese various angles are adjustable and may be equal to one another ordifferent from one another. 1901 and 1902 are folding or pivoting axescomprising mechanical and electrical connectors in partially expandedposition. FIG. 19C shows the closed structure of FIGS. 19A-B in afurther extended condition.

SPS Building Block Electrical and Mechanical Attachment Leads

FIG. 20A show representative example of an SPS building block electricaland mechanical attachment leads. This particular example shows rigidround wires which provide both mechanical (structural) and electricalsupport. In this example both sides have both positive and negativewires. In some other embodiment, one side of the module may have only apositive lead, while the other side has only a negative lead. Instead ofround wire, positive or negative leads can be made of rigid ribbonconnection. Ribbon connections can have dimension shorter than the fullwidth of the SPS building block, or can cover the entire width of theSPS building block.

Referring back to the example of FIG. 20A, two pairs of electrical leads2020 and 2021 provided as rigid metallic (e.g., copper or aluminum ortheir alloys) cylindrical wires from the opposite shorter sides of theSPS building block (positive & negative lead wires available on bothends). Wire leads are used for electrical and mechanical connections tothe RDP-SPG folding (or pivoting) sheet connectors.

In the example shown in FIG. 20A, Z=1, S=4, M=3×3 (dimensions not shownto relative scale). The multi-modal MPPT chip 2009 is on the in-laminateframe 2001.

FIG. 20B shows the cross-sectional view along the plane AA shown in FIG.20A. Thin (e.g., 0.025 to 0.500 mm) transparent Fluoroplastic (or Glass)cover sheet 2005 on face 1 and cover sheet 2006 on face 2 of the SPSunit protects the solar cells. Solar encapsulant layers 2007 and 2008(e.g. EVA or POE or IBE) is used to encapsulate bifacial sides 1 and 2of the sub-cells 2002.

The SPS building block units (each SPS unit having one or two pairs ofconnectors, for instance, combined electrical and mechanical connectorsprovided by the SPS frame protrusions or extensions at the shorter sidesof the SPS units), may be easily attached to a pair of retractable &expandable folding (or pivoting) sheet connectors through one of anumber of possible RDP-SPG design configurations, as follows:

-   -   Snap-in connections of the wire leads from the SPS units into        the sheet connectors (for the designs using 1 or 2 pairs of        rigid round wire leads, with the wires having a snap-in design;    -   Snap-in connections of the ribbon leads from the SPS units into        the sheet connectors (for the designs using 1 or 2 pairs of        rigid ribbon leads, with the ribbons having a snap-in design.

There are other possible designs for easy plugging of the SPS units intothe sheet connectors. For example, notches or teeth in the frameextension can keep the SPS units attached to the sheet connectors afterthey are plugged in. The SPS frame extension may have copper covering,serving as mechanical and electrical connector.

Various Applications and Markets for the RDP-SPG Modules

Some possible applications for the RDP-SPG module include, but are notlimited to the following:

-   -   Portable chargers for consumer power-on-the-go applications (˜30        W to ˜100 W modules);    -   Portable uninterrupted power supplies (e.g., ˜100 W to 300 W        modules);    -   Transportable modules for recreational vehicles and applications        (˜300 W to 1 kW modules);    -   Transportable modules for military applications (˜300 W to ˜1 kW        modules);    -   Transportable electric vehicle chargers (˜1.5 kW to 3 kW        deployable canopies; 20-40 miles/day);    -   Quick-install residential & commercial applications (˜300 W to 1        kW)—The RDP-SPG modules can be rapidly deployed and retracted        for removal or relocation in these applications, either as        rooftop modules or as lay-on-the-ground super-fast-install PV        modules;    -   Portable power generators (˜100 to 400 W modules) for the places        where electrical infrastructure is inadequate. A wide range of        other off-grid and grid-tied as well as portable and        transportable power applications are possible.

FIG. 21 shows a table showing various representative preferred SPSbuilding block unit and RDP-SPG module designs. In this table. E-cutmeans electrical cut, and M-cut means mechanical cut. V_(oc) is opencircuit voltage, and I_(sc) is STC short-circuit current.

To summarize, this disclosure teaches various embodiments of RDP-SPGmodules. Some non-limiting illustrative structural attributes of the SPSbuilding block units are:

-   -   Each unit is (semi) rigid, planar, and elongated (preferably        rectangular) with aspect ratio of ˜2 to ˜20;    -   Each unit is thin (≤3 mm), and lightweight to provide high power        density (˜50 W_(p)/kg to ˜200 W_(p)/kg);    -   Each unit has a thin (<3 mm) in-laminate composite polymeric        frame (e.g., made from light-density glass-filled polymers such        as Ultramid or Ultradur or FR4 or other fiber-reinforced        composites) for mechanical rigidity and support;    -   Each unit is bifacial to receive and convert light to        electricity on both its opposite faces;    -   Each unit uses sub-cells based on a partitioning pattern        providing a plurality of M=K×L (2≤M≤16; K & L from 1 to 8)        bifacial sub-cells made from full bifacial solar cells using 1        to 5 electrical cuts;    -   Each unit uses at least one in-laminate super-cell having a        plurality of (at least 10) sub-cells which are electrically        connected together either as all-series or as hybrid        parallel-series connections, and with super-cell voltage        scale-up factor of 10 to 16, and current scale-down factor of 2        to 6, and super-cell block power in the preferred range of about        10 W_(p) to ˜30 W_(p) per super-cell;    -   Arranged either as co-planar sub-cells or edge-overlapping        sub-cells (with the latter sub-cell arrangement providing higher        power densities than the co-planar arrangement);    -   Each unit uses at least one multi-modal MPPT chip attached to        the power leads of the super-cell;    -   Each unit has a laminate structure with a pair of durable,        high-optical transmissivity, impact resistant, weather        resistant, flame resistant, lightweight, thermally stable,        protective cover sheets (preferably ˜0.025 to 0.125 mm thick        sheets of fluoroplastics such as ETFE or FEP);    -   Each unit uses a pair of transparent encapsulant sheets (EVA,        POE, or IBE) under both cover sheets;    -   Each unit has at least a pair of electrical leads (positive &        negative power leads) on one or both shorter sides;    -   Each unit has mechanical connectors on both (and electrical        connectors on 1 or both) shorter sides.

Some non-limiting illustrative structural attributes of the RDP-SPGmodules are:

-   -   A module can have at least U=2 and up to U=45 bifacial SPS        building block units used in its structure;    -   A module has U×Z multi-modal MPPT power optimizer chips attached        to or embedded within the SPS building block units (Z is the        number of super-cells per SPS building block unit and is        typically between 1 and 5);    -   Provides a volume compaction ratio (ratio of the module's        virtual enclosure volume when fully expanded to the module's        virtual enclosure volume when fully retracted) of at least 10        and up to over 100, with typical module volume compaction ratios        of 50 to 100;    -   Can be made using various design configurations, such as:        -   1. Open Structure (or Parallel-Spaced Structure) wherein the            SPS building block units are spaced apart from each other            (not contacting each other directly in the expanded or            deployed mode; but stacked on each other when retracted),            are parallel to one another, and can be either perpendicular            (fixed 90° angle) or non-perpendicular (tilted with an angle            of <90°) with respect to its virtual enclosure planes; the            Open-Structure RDP-SPG modules may have a fixed SPS angle            (perpendicular or tilted non-perpendicular), or may be            designed to allow for adjustable SPS-to-virtual plane tilt            angle in a range between 0° to 90°. The Open-Structure            RDP-SPG modules utilize a pair of adjustable folding (or            pivoting or hinged) thin sheet or framed connectors attached            to the shorter sides of the SPS building blocks, providing            electrical & mechanical connections to the SPS building            blocks and allowance for full scale retraction and expansion            of module. The Open-Structure RDP-SPG modules have            negligible wind resistance forces, enabling easy drop-in            outdoor installations in applications susceptible to high            winds (e.g., commercial & industrial rooftop PV power            generation.)        -   2. Closed Structure (or Connected Structure) wherein the            adjacent SPS building block units are physically connected            to each other (either on their longer sides or on their            shorter sides), and are angled with respect to each other            (with adjacent SPS-to-SPS angle of greater than 0° to less            than 360° when deployed for power generation, or a subset            thereof; the adjacent SPS-to-SPS angles=˜0° or ˜360° when in            fully retracted mode); the Closed-Structure (or Connected            Structure) RDP-SPG modules provide capability and allowance            for adjusting the individual SPS-to-SPS plan angles between            each pair of the adjacent SPS building block units, and            various angles for various adjacent SPS pairs in the module            may have equal or dissimilar SPS-pair angles.

The included descriptions and figures depict specific implementations toteach those skilled in the art how to make and use the best mode. Forthe purpose of teaching inventive principles, some conventional aspectshave been simplified or omitted. Those skilled in the art willappreciate variations from these implementations that fall within thescope of the disclosure. Those skilled in the art will also appreciatethat the features described above can be combined in various ways toform multiple implementations. As a result, the disclosure is notlimited to the specific implementations described above, but only by theclaims and their equivalents.

What is claimed is:
 1. A portable solar photovoltaic (PV) electricitygenerator module comprising: a plurality of parallel smart power slat(SPS) units, each SPS unit having two shorter sides and two longersides, and said each SPS unit comprising a laminate comprising: a singlelayer of a plurality of coplanar bifacial solar cells having electricalcuts substantially parallel to said shorter sides and electricallyconnected together along said longer sides based on a specified cellinterconnection design; an in-laminate single-piece continuousperipheral frame made of a lightweight electrically-insulating and rigidcomposite material for surrounding and structurally supporting saidsingle layer of a plurality of coplanar bifacial solar cells havingelectrical cuts, wherein said composite material is one material or acombination of materials comprising injection-moldable compositeglass-reinforced polyamide materials or injection-moldable compositeglass-reinforced polybutylene terephthalate materials having a massdensity of less than 1.9 grams per cubic centimeter; and at least onepower maximizing integrated circuit collecting electricity generated bythe plurality of solar cells; wherein the plurality of parallel SPSunits are mechanically connected such that the SPS units can beretracted for volume compaction of the module, and can be expanded forincreasing PV electricity generation by the module; wherein acollapsible mechanical connector attached to the plurality of parallelSPS units has a first part and a second part, the first part comprisinga folding thin-sheet connector connecting one edge of all the SPS units,and the second part comprising a folding thin-sheet connector connectingthe opposite edge of all the parallel SPS units, thereby producing arapidly retractable and expandable module structure, where all theparallel SPS units are structurally and electrically connected.
 2. Thegenerator module of claim 1, wherein the plurality of coplanar solarcells having electrical cuts are bifacial crystalline solar cells. 3.The generator module of claim 2, wherein the bifacial crystalline solarcells comprise monocrystalline silicon solar cells.
 4. The generatormodule of claim 3, wherein the bifacial crystalline solar cells comprisemonocrystalline silicon heterojunction solar cells.
 5. The generatormodule of claim 2, wherein the bifacial crystalline solar cells have STCconversion efficiency of approximately 21% or more, and comprisebifacial silicon passivated-emitter rear contact (PERC) solar cells orbifacial silicon heterojunction solar cells.
 6. The generator module ofclaim 1, wherein the specified cell interconnection design connects theplurality of coplanar solar cells having electrical cuts in electricalseries or a hybrid of electrical parallel and series.
 7. The generatormodule of claim 1, wherein the laminate of each SPS unit comprises anoptically transparent protective cover sheet comprising a fluoropolymermaterial.
 8. The generator module of claim 1, wherein the in-laminateframe of each SPS unit nests and structurally supports the coplanarsolar cells having electrical cuts.
 9. The generator module of claim 8,wherein the lightweight composite material is an injection moldablecomposite material made of a combination of a polymeric material andglass fibers providing high mechanical strength, rigidity, impactresistance, and thermal stability.
 10. The generator module of claim 9,wherein the polymeric material is a glass-fiber reinforced polyamide.11. The generator module of claim 1, wherein each SPS unit generates apeak solar PV power in the range of about 10-100 watts.
 12. Thegenerator module of claim 1, wherein the module delivers DC electricpower output to one or both of a storage battery and a DC consumptionload.
 13. The generator module of claim 1, wherein the module deliversAC electric power output to an AC consumption load.
 14. The generatormodule of claim 1, wherein each SPS unit has electrical power leadsconnected to output power leads of the at least one power maximizingintegrated circuit collecting electricity generated by the plurality ofcoplanar solar cells having electrical cuts in that SPS unit.
 15. Thegenerator module of claim 14, wherein output power leads of all thepower maximizing integrated circuits in the module are connectedtogether according to an electrical interconnection design to deliverpower generated by the module with a desired electrical voltage andcurrent ranges.
 16. The generator module of claim 15, wherein theelectrical interconnection design connects the output power leads of thepower maximizing integrated circuits in electrical series or a hybrid ofelectrical parallel and series.
 17. The generator module of claim 1,wherein the plurality of power maximizing integrated circuits operatecooperatively with a maximum-power-point-tracking (MPPT) power optimizerconnected to the module's power delivery leads.
 18. The generator moduleof claim 1, wherein a volume compaction ratio for the module is in therange of 10 to 100, wherein there is negligible spacing between adjacentparallel SPS units when the module is fully retracted for storage orportability.
 19. The generator module of claim 1, wherein the first partand the second part of the collapsible mechanical connector comprisehinged connectors that pivot around the hinges.
 20. The generator moduleof claim 1, wherein each SPS unit has a slat length larger than a slatwidth, and both slat length and slat width being substantially largerthan a slat thickness.
 21. The generator module of claim 20, wherein theslat width ranges between half the width of a non-partitionedcrystalline solar cell without electrical cuts and twice the width of anon-partitioned crystalline solar cell without electrical cuts.
 22. Thegenerator module of claim 1, wherein each power maximizing integratedcircuit is a multi-modal MPPT integrated circuit.